From times immemorial, man has steeped solid matter in liquids, either to have the liquid selectively affect the solid matter or vice versa, and sometimes both. Usually, the liquid and the solid matter are placed in a vessel, which at times itself participates to the maceration process, and left to interact for a set length of time under specified conditions. When the maceration process has reached the stage deemed best and final, either component or both are extracted, either altogether at once or as needed, until the vessel is empty. Then the vessel is cleaned and readied for use once more. Very seldom is it advisable and proper to add more liquid and/or solid matter at any time after the steeping process is initiated. In such instance, one refers to this as a batch process in our modern times. Such an approach to maceration is quite limitative in terms of both production continuity and product quality consistency.
The types and natures of the liquids in which solid matter is steeped are numerous and varied. The types, natures and combinations thereof of solid materials used to affect the liquids in which they are caused to steep are even more numerous and varied. The end results and their uses were and still are a significant part of fields of human endeavors such as medicine (internal and external), cooking, eating and drinking for enjoyment and pleasurable gratification.
Because many households have different needs and tastes, and wish to utilize some of the products that they use or consume in specific ways to satisfy fully such needs and tastes, and because these might prove to be either to expensive or not even practically possible, many such households simply are prevented from producing their own special ingredients. The rate of consumption of such special ingredients on a household scale is also small. Batch processing of the components required to produce such special ingredients is most likely too cumbersome, inefficient and inadequate, thus resulting in waste and the likelihood of lower quality products being thus obtained.